1. Field of the Invention
The present invention relates to a lens device and more particularly, to a lens device having a function of adjusting the tilt of a lens.
2. Description of the Related Art
It is necessary to attach each lens without inclining the lens in order to obtain a desired optical performance of a lens device. Therefore, it is preferable that the lens device have a function of adjusting the tilt of the lens during assembly.
As the lens device having a mechanism for adjusting the tilt of a lens, JP-A-2004-163865 (corresponding to US-A-2004/0109243) discloses a lens device in which adjustment pins are provided on at least three points on the outer circumferential surface of a barrel body and the adjustment pins are rotated to displace a lens holding member in the optical axis direction, thereby adjusting the tilt of a lens.
JP-A-2007-279525 (corresponding to US-A-2007/0236808) discloses a structure in which at least three supporting portions that support a lens holding frame such that the position of the lens holding frame can be changed relative to a barrel body, one of the three supporting portions supports the lens holding frame with a spherical surface, and the other supporting portions support the lens holding frame such that the gap between the lens holding frame and the barrel body can be adjusted, and the tilt of a lens is adjusted by adjusting the gap between the lens holding frame and the barrel body.
However, the tilt of the lens is adjusted as follows. For example, a laser autocollimator is used to detect the tilt of the lens and the tilt of the lens is corrected on the basis of the detection result. The adjustment mechanism according to the related art has a problem in that it takes a long time to calculate the amount of adjustment of each adjustment member (the amount of rotation of each adjustment pin in JP-A-2004-163865 and the gap between the supporting portions in JP-A-2007-279525) and it is necessary to correct the tilt of the lens while performing fine adjustment several times.